Control systems for electronically controlled valves control many different types of fluids for many different purposes. While control systems, their controllers, and the associated electronically controlled valves have many benefits, these control systems, controllers, electronically controlled valves and portions thereof may still be improved.
For instance, certain electronically controlled valves have a spool that is disposed within a valve body of the valves. The spool is configured to valve fluid between the inlet and outlet of the valves. With many of these valves, there is a “stiction” that occurs when the valve is placed in a single position for some time period. Such stiction can cause, for instance, a lack of response initially to an increase in control signals applied to an electronic actuator of the valve. In other words, the spool becomes “stuck” and lacks initial responsiveness. Increasing the value of the control signal will cause the spool to become unstuck, but a lack of fine control results. To reduce stiction, mechanical dither is used, where the spool itself is made to vibrate. The vibration reduces or eliminates stiction. However, systems for creating mechanical dither could be improved.